Summary Unit 4

about how many alveoli are there

~300 million

What is the surface area of alveoli?

760 sq ft

Respiratory membrane

Extremely thin layer between alveolar cell and capillary endothelial cells

Pathway of oxygen

Trachea —> primary, secondary, tertiary bronchi —> terminal bronchioles —> respiratory bronchioles —> alveolar sacs

Intrapulmonary pressure difference in Inspiration and expiration

inspiration: -1

expiration: +1

intrapleural pressure difference in Inspiration and expiration

inspiration: -8

expiration: -5

transpulmonary pressure difference in Inspiration and expiration

Inspiration: +7

Expiration: +6

Lung volume and intrapulmonary pressure during inspiration

lung volume increases, intrapulmonary pressure decreases

Lung volume and intrapulmonary pressure during expiration

lung volume decreases, intrapulmonary pressure increases

what is the primary muscle of ventilation?

diaphragm

If pH decreases, the affinity for oxygen (increases/decreases)

decreases

If temperature increases, the affinity for oxygen (increases/decreases)

decreases

If 2,3 DPG increases, the affinity for oxygen (increases/decreases)

decreases decreases due to an increase in red blood cell metabolism, which promotes oxygen release.

What causes a reduced affinity of hemoglobin for oxygen?

decreased pH, increased temperature and increased 2,3DPG

What does it mean if there is reduced affinity of hemoglobin for oxygen?

more oxygen is delivered to tissues

4 functions of kidneys

1. blood volume

2. waste

3. electrolytes

4. pH

2 parts of the kidney

1. cortex

2. medulla

2 parts of the kidney medulla

pyramids and columns

Pathway of urine

pyramid —> minor and major calyx —> renal pelvis —> ureter —> urinary bladder —> urethra

what are neprhons made of?

tubules and associated small blood vessels

Flow of filtrate within a nephron

Glomerular (Bownman’s capsule) —> proximal convulted tubule —> loop of Henle

blood flow in the kidney

Afferent arterioles → glomerulus → efferent arteriole

process of renal plasma clearance

filtration —> reabsorption —> secretion

Filtration happens where in the kidney

bowman’s capsule

where does reabsorption happen in the kidneys?

proximal convoluted tubule/ descending loop of henle

where does secretion occur in the kidney?

nephron tubule

5 functions of the digestive tract

1. deglutition

2. mastication

3. peristalsis

4. digestion

5. absorption

GI tract

oral cavity —> pharynx —> esophagus —> stomach —> small intestines —> large intestines

Chyme

a semi-liquid mixture of partially digested food and digestive juices that forms in the stomach and is then released into the small intestine.

Gastric pits of the stomach

mucus neck cell, pareital cell, chief cell

The mucus neck cell secretes

mucus

the parietal cell secretes

HCl and intrinsic factor

The chief cell secretes

pepsinogen

Gastric rugae

folds in the stomach lining

Small intestine parts

include the duodenum, jejunum, and ileum.

Plicae circulares

circular folds of the small intestine that increase surface area for absorption

Villi

microscopic projections on the intestinal wall that increase surface area for absorption.

Microvilli

tiny hair-like projections on the surface of villi that further increase the effective surface area for nutrient absorption.

3 Brush border enzymes

1. disaccharidase

2. peptidase

3. phosphatase

Disaccharidase

hydrolyze disaccharides

peptidase

enzymes that hydrolyze peptides

phosphatase

enzymes that remove phosphate groups

flow of bile within the liver lobule

bile canaliculi → bile ductile → bile duct

flow of blood within the liver lobule

Hepatic portal vein/ Hepatic artery → sinusoids → central vein

4 Functions of the liver

1. bile production

2. detoxification

3. carb, triglyceride and cholesterol metabolism

4. plasma protein production

Composition of pancreatic juice

bicarbonate + pancreatic enzymes

Carbohydrate enzymes

amylase and brush border enzymes

6 Protein digestive enzymes

1. pepsin

2. trypsin

3. chymotrypsin

4. elastase

5. carboxypeptidase

6. brush border enyzme

lipid digestive enzyme

lipase

Enterokinase activates

trypsinogen to trypsin.

function of trypsin, chymotrypsin and elastase

cleave internal perptide bonds

Function of carboxypeptidase

claves last amino acid from carboxyl-terminal end of polypeptide

Phospholipase function

cleaves fatty acids from phospholipids such as lecithin

Lipase function

cleaves fatty acids from glyceol

amylase function

digests starch to maltose and short chains of glucose

Function of cholesterolesterase

releases cholesterol from its bonds with other molecules

Function of ribonuclease

cleaves RNA to form short chains

function of deoxyribonuclease

cleaves DNA to form short chains

Parts of the testes

seminiferous tubules and interstitital tissue

what produces sperm?

seminiferous tubules

what produces testosterone

leydig cells in the interstitial tissue

Sequence of sperm transport

Seminiferous tubules → rete testis → efferent ductules → epididymis → ductus
deferens → ejaculatory duct → urethra

How is semen made?

the seminal vesicle/prostate gland adds fluid to sperm

parts of the female reproductive system

ovary, uterine tubes, uterus

4 parts of the uterus

1. endometrium

2. myometrium

3. perimetrium

4. cervix

endometrium

inner layer wehre embryo implants and develops

myometrium

middle layer which contracts to expel baby at birth

Perimetrium

outer connective tissue layer

cervix

narrow bottom region of uterus

Ovarian cycle

follicular phase, lueteal phase, ovulation

progression of follicular stage

(primary follicles → secondary follicles → mature (Graafian)
follicles

what hormone promotes ovulation

LH

luteal phase

the formation of the corpus lueteum

what does the corpus luteum secrete?

estradiol and progesterone

what happens to the corpus lueteum if it’s not fertilized

It degenerates into the corpus albicans.

The menstrual cycle phases

proliferative, secretory, menstrual

proliferative phase

occurs when the ovary is in the follicular phase

secretory phase

occurs while the ovaries are in the luteal phase

menstrual phase

occurs as a result of the fall in estradiol and progesterone when the corpus luteum degenerates

what happens in the proliferative phase?

spiral arteries develop and the endometrium becomes more vascular and develops progesterone receptors

what happens in the secretory phase?

the endometrium becomes thicker and more vascular as it’s prepared to nourish a growing embryo